Tomoxetine, (-)-N-methyl-3-(2-methylphenoxy)-3-phenylpropylamine, is a valuable compound capable of treating humans suffering from depression. The synthesis currently employed to manufacture tomoxetine produces a racemic mixture which must be resolved to the appropriate (-) isomer.
The resolution of racemic (+-)-N-methyl-3-(2-methylphenoxy)-3-phenylpropylamine produces significant quantities of the undesired (+) isomer. The (+) isomer generally has been discarded because there has been no inexpensive and efficient method of converting it to the desired (-) isomer. The present invention provides a process for epimerizing the (+) isomer to its racemic form, which can then be quickly and economically converted to the desired (-) isomer, tomoxetine.